package com.rms.utils;

import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.exceptions.JWTVerificationException;
import com.rms.entity.Admin;
import com.rms.service.AdminService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Method;

/**
 * @author 胡满意
 * @date 2019/10/24
 */
@Component
public class LoginInterceptor implements HandlerInterceptor {
    @Autowired
    private AdminService adminService;
    private RedirectionAjax redirectionAjax  = new RedirectionAjax();

    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object object) throws Exception {
        String token = httpServletRequest.getHeader("token");

        // 从 http 请求头中取出 token
        // 如果不是映射到方法直接通过
        if(!(object instanceof HandlerMethod)){
            return true;
        }
        HandlerMethod handlerMethod=(HandlerMethod)object;
        Method method=handlerMethod.getMethod();
        //检查是否有passtoken注释，有则跳过认证
        if (method.isAnnotationPresent(PassToken.class)) {
            PassToken passToken = method.getAnnotation(PassToken.class);
            if (passToken.required()) {
                return true;
            }
        }
        //检查有没有需要用户权限的注解
        if (method.isAnnotationPresent(UserLoginToken.class)) {
            UserLoginToken userLoginToken = method.getAnnotation(UserLoginToken.class);
            if (userLoginToken.required()) {
                // 执行认证
                if (token == null) {
                    System.out.println("noToken");
                    if (redirectionAjax.isAjaxRequest(httpServletRequest,httpServletResponse)){
                        redirectionAjax.ajaxHttpToLogin(httpServletRequest,httpServletResponse,"/login.html");
                        return false;
                    }
                    httpServletResponse.sendRedirect(httpServletRequest.getContextPath()+"/login.html");
//                    throw new RuntimeException("无token，请重新登录");
                    return false;
                }
                // 获取 token 中的 adminId
                String adminId;
                try {
                    adminId = JWT.decode(token).getAudience().get(0);
                } catch (JWTDecodeException j) {
//                    throw new RuntimeException("401");
                    System.out.println("noAdminId");
                    if (redirectionAjax.isAjaxRequest(httpServletRequest,httpServletResponse)){
                        redirectionAjax.ajaxHttpToLogin(httpServletRequest,httpServletResponse,"/login.html");
                        return false;
                    }
                    httpServletResponse.sendRedirect(httpServletRequest.getContextPath()+"/login.html");
                    return false;
                }
                Admin admin = adminService.selectAdmin(Integer.parseInt(adminId));
                if (admin == null) {
                    System.out.println("noAdmin");
                    if (redirectionAjax.isAjaxRequest(httpServletRequest,httpServletResponse)){
                        redirectionAjax.ajaxHttpToLogin(httpServletRequest,httpServletResponse,"/login.html");
                        return false;
                    }
//                    throw new RuntimeException("用户不存在，请重新登录");
                    httpServletResponse.sendRedirect(httpServletRequest.getContextPath()+"/login.html");
                    return false;
                }
                // 验证 token
                JWTVerifier jwtVerifier = JWT.require(Algorithm.HMAC256(admin.getAdminPassword())).build();
                try {
                    jwtVerifier.verify(token);
                } catch (JWTVerificationException e) {
//                    throw new RuntimeException("401");
                    System.out.println("tokenError");
                    if (redirectionAjax.isAjaxRequest(httpServletRequest,httpServletResponse)){
                        redirectionAjax.ajaxHttpToLogin(httpServletRequest,httpServletResponse,"/login.html");
                        return false;
                    }
                    httpServletResponse.sendRedirect(httpServletRequest.getContextPath()+"/login.html");
                    return false;
                }
                return true;
            }
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest,
                           HttpServletResponse httpServletResponse,
                           Object o, ModelAndView modelAndView) throws Exception {

    }
    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest,
                                HttpServletResponse httpServletResponse,
                                Object o, Exception e) throws Exception {
    }

}
